The only question in the climate debate is “does human emission of CO2 causes global warming?” One way to answer this question is to compare IPCC’s model projections for the global mean temperature with actual observations (hadcrut3 data) as shown in the above chart.

The above result shows IPCC projections are wrong. Actually, the observed global mean temperatures are even less than the projections if emission were held constant at year 2000 level, as shown by the orange curve in the above chart.

It is extremely crucial that public policy be based on facts. The above data shows, human emission of CO2 does not cause global warming.

Comparison of the claims by the Intergovernmental Panel on Climate Change (IPCC) of 1) “Most of the observed increase in global average temperatures since the mid-20th century is very likely” man made, and 2) “For the next two decades a warming rate of 0.2 deg C per decade is projected” are shown in this article not to be supported by the observed data, thus disproving IPCC’s theory of man made global warming.

FIRST IPCC CLAIM

In its Fourth Assessment Report of 2007, IPCC’s claim regarding global warming was the following [1]:

Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.

Let us verify this claim using the observed data from the Climate Research Unit (CRU) of the University of East Anglia [2]. In this claim, “mid-20th century” means year 1950. As a result, according to the IPCC, global warming since 1950 is mostly man made.

To verify the claim that global warming since 1950 is mostly man made, we may compare the global warming rate in degree centigrade (deg C) per decade in one period before 1950 to that of a second period after 1950 to determine the effect of the increased human emission of CO2. To be able to do this, we need to identify these two periods, which may be established from the Global Mean Temperature Anomaly (GMTA) data of the CRU.

This is a scientific question and can be answered using the scientific method with observed global mean temperature data.

A graph of global mean temperature from the Climate Research Unit of the University of East Anglia is shown in the above graph [1].

The first period is from 1910 to 1940 & the second period is 60-years latter from 1970 to 2000. After human emission of CO2 for 60-years, the rate of change of global mean temperature of 0.15 deg C per decade from 1970 to 2000 is nearly identical to that of 0.16 deg C per decade from 1910 to 1940. That is, after a 5-times increase in human emission of CO2, there was no increase in the rate of increase of global mean temperature. This data contradicts the theory that human emission of CO2 causes global warming.

The observed yearly Global Mean Temperature from the Climate Research Unit can be modelled by a combination of linear and sinusoidal functions as shown in chart above.

As shown in the chart above, if the global mean temperature cycle behaves the way it behaved for the last 130 years, there will be global cooling until 2030. In contrast, the IPCC projections that started its divergence away from observed temperature about 2005 will continue its imaginary trajectory towards its exaggerated target temperature.

The main issue we seek in the global warming debate is the truth. The only question in this debate is “Does human emission of CO2 causes global warming?”

One way to answer this question is to verify the IPCC projections for the mean global temperature anomaly that states [1]

For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios.

This result can be verified by comparing it with actual measurement (hadcrut3 [2]) as shown in the chart above, which shows IPCC projection is incorrect. Actually, the observed mean global temperatures anomalies are even less than the projections with emission commitment held constant at year 2000 values, as shown by the orange curve in the above chart.

CO2 is known to be a heat trapping greenhouse gas. The theory of man made global warming assumes that the CO2 in the atmosphere (about 0.04% of air) that has increased due to use of fossil fuels by humans has been causing global warming.

In science, the method used to verify the validity of a theory is to compare the theory with actual observations. To verify the theory of man made global warming, we may compare the change in CO2 in the atmosphere to change in mean global temperature during the same period.

The main issue in the global warming debate is the truth. The only question in this debate is “does human emission of CO2 causes global warming?” One way to answer this question is to compare the IPCC projections for the mean global temperature anomaly with actual measurements as shown in the above chart.

They say that this global warming was caused by CO2 and will increase up to 6 deg C by 2100.

We strongly disagree. We say the global temperature is oscillatory with increasing and decreasing temperatures, but the CO2 level has only been increasing. We also say that before 1900, since the little ice age, global temperature had been increasing. From 1976 to 1998, both CO2 and mean global temperature had been increasing. This does not mean that this correlation is always valid.